1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * List pending timers 4 * 5 * Copyright(C) 2006, Red Hat, Inc., Ingo Molnar 6 */ 7 8 #include <linux/proc_fs.h> 9 #include <linux/module.h> 10 #include <linux/spinlock.h> 11 #include <linux/sched.h> 12 #include <linux/seq_file.h> 13 #include <linux/kallsyms.h> 14 #include <linux/nmi.h> 15 16 #include <linux/uaccess.h> 17 18 #include "tick-internal.h" 19 20 struct timer_list_iter { 21 int cpu; 22 bool second_pass; 23 u64 now; 24 }; 25 26 /* 27 * This allows printing both to /proc/timer_list and 28 * to the console (on SysRq-Q): 29 */ 30 __printf(2, 3) 31 static void SEQ_printf(struct seq_file *m, const char *fmt, ...) 32 { 33 va_list args; 34 35 va_start(args, fmt); 36 37 if (m) 38 seq_vprintf(m, fmt, args); 39 else 40 vprintk(fmt, args); 41 42 va_end(args); 43 } 44 45 static void 46 print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer, 47 int idx, u64 now) 48 { 49 SEQ_printf(m, " #%d: <%p>, %ps", idx, taddr, ACCESS_PRIVATE(timer, function)); 50 SEQ_printf(m, ", S:%02x", timer->is_queued); 51 SEQ_printf(m, "\n"); 52 SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n", 53 (unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)), 54 (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)), 55 (long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now), 56 (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now)); 57 } 58 59 static void print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base, u64 now) 60 { 61 struct timerqueue_linked_node *curr; 62 struct hrtimer *timer, tmp; 63 unsigned long next = 0, i; 64 unsigned long flags; 65 66 next_one: 67 i = 0; 68 69 touch_nmi_watchdog(); 70 71 raw_spin_lock_irqsave(&base->cpu_base->lock, flags); 72 73 curr = timerqueue_linked_first(&base->active); 74 /* 75 * Crude but we have to do this O(N*N) thing, because 76 * we have to unlock the base when printing: 77 */ 78 while (curr && i < next) { 79 curr = timerqueue_linked_next(curr); 80 i++; 81 } 82 83 if (curr) { 84 85 timer = container_of(curr, struct hrtimer, node); 86 tmp = *timer; 87 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags); 88 89 print_timer(m, timer, &tmp, i, now); 90 next++; 91 goto next_one; 92 } 93 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags); 94 } 95 96 static void 97 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now) 98 { 99 SEQ_printf(m, " .base: %p\n", base); 100 SEQ_printf(m, " .index: %d\n", base->index); 101 102 SEQ_printf(m, " .resolution: %u nsecs\n", hrtimer_resolution); 103 #ifdef CONFIG_HIGH_RES_TIMERS 104 SEQ_printf(m, " .offset: %Ld nsecs\n", 105 (long long) base->offset); 106 #endif 107 SEQ_printf(m, "active timers:\n"); 108 print_active_timers(m, base, now + ktime_to_ns(base->offset)); 109 } 110 111 static void print_cpu(struct seq_file *m, int cpu, u64 now) 112 { 113 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); 114 int i; 115 116 SEQ_printf(m, "cpu: %d\n", cpu); 117 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { 118 SEQ_printf(m, " clock %d:\n", i); 119 print_base(m, cpu_base->clock_base + i, now); 120 } 121 #define P(x) \ 122 SEQ_printf(m, " .%-15s: %Lu\n", #x, \ 123 (unsigned long long)(cpu_base->x)) 124 #define P_ns(x) \ 125 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \ 126 (unsigned long long)(ktime_to_ns(cpu_base->x))) 127 128 #ifdef CONFIG_HIGH_RES_TIMERS 129 P_ns(expires_next); 130 P(hres_active); 131 P(nr_events); 132 P(nr_retries); 133 P(nr_hangs); 134 P(max_hang_time); 135 #endif 136 #undef P 137 #undef P_ns 138 139 #ifdef CONFIG_TICK_ONESHOT 140 # define P(x) \ 141 SEQ_printf(m, " .%-15s: %Lu\n", #x, \ 142 (unsigned long long)(ts->x)) 143 # define P_ns(x) \ 144 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \ 145 (unsigned long long)(ktime_to_ns(ts->x))) 146 # define P_flag(x, f) \ 147 SEQ_printf(m, " .%-15s: %d\n", #x, !!(ts->flags & (f))) 148 149 { 150 struct tick_sched *ts = tick_get_tick_sched(cpu); 151 P_flag(nohz, TS_FLAG_NOHZ); 152 P_flag(highres, TS_FLAG_HIGHRES); 153 P_ns(last_tick); 154 P_flag(tick_stopped, TS_FLAG_STOPPED); 155 P(idle_jiffies); 156 P(idle_calls); 157 P(idle_sleeps); 158 P_ns(idle_entrytime); 159 P_ns(idle_waketime); 160 P_ns(idle_exittime); 161 P_ns(idle_sleeptime); 162 P_ns(iowait_sleeptime); 163 P(last_jiffies); 164 P(next_timer); 165 P_ns(idle_expires); 166 SEQ_printf(m, "jiffies: %Lu\n", 167 (unsigned long long)jiffies); 168 } 169 #endif 170 171 #undef P 172 #undef P_ns 173 SEQ_printf(m, "\n"); 174 } 175 176 #ifdef CONFIG_GENERIC_CLOCKEVENTS 177 static void 178 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) 179 { 180 struct clock_event_device *dev = td->evtdev; 181 182 touch_nmi_watchdog(); 183 184 SEQ_printf(m, "Tick Device: mode: %d\n", td->mode); 185 if (cpu < 0) 186 SEQ_printf(m, "Broadcast device\n"); 187 else 188 SEQ_printf(m, "Per CPU device: %d\n", cpu); 189 190 SEQ_printf(m, "Clock Event Device: "); 191 if (!dev) { 192 SEQ_printf(m, "<NULL>\n"); 193 return; 194 } 195 SEQ_printf(m, "%s\n", dev->name); 196 SEQ_printf(m, " max_delta_ns: %llu\n", 197 (unsigned long long) dev->max_delta_ns); 198 SEQ_printf(m, " min_delta_ns: %llu\n", 199 (unsigned long long) dev->min_delta_ns); 200 SEQ_printf(m, " mult: %u\n", dev->mult); 201 SEQ_printf(m, " shift: %u\n", dev->shift); 202 SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev)); 203 SEQ_printf(m, " next_event: %Ld nsecs\n", 204 (unsigned long long) ktime_to_ns(dev->next_event)); 205 206 SEQ_printf(m, " set_next_event: %ps\n", dev->set_next_event); 207 208 if (dev->set_state_shutdown) 209 SEQ_printf(m, " shutdown: %ps\n", 210 dev->set_state_shutdown); 211 212 if (dev->set_state_periodic) 213 SEQ_printf(m, " periodic: %ps\n", 214 dev->set_state_periodic); 215 216 if (dev->set_state_oneshot) 217 SEQ_printf(m, " oneshot: %ps\n", 218 dev->set_state_oneshot); 219 220 if (dev->set_state_oneshot_stopped) 221 SEQ_printf(m, " oneshot stopped: %ps\n", 222 dev->set_state_oneshot_stopped); 223 224 if (dev->tick_resume) 225 SEQ_printf(m, " resume: %ps\n", 226 dev->tick_resume); 227 228 SEQ_printf(m, " event_handler: %ps\n", dev->event_handler); 229 SEQ_printf(m, "\n"); 230 SEQ_printf(m, " retries: %lu\n", dev->retries); 231 232 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 233 if (cpu >= 0) { 234 const struct clock_event_device *wd = tick_get_wakeup_device(cpu); 235 236 SEQ_printf(m, "Wakeup Device: %s\n", wd ? wd->name : "<NULL>"); 237 } 238 #endif 239 SEQ_printf(m, "\n"); 240 } 241 242 static void timer_list_show_tickdevices_header(struct seq_file *m) 243 { 244 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 245 print_tickdevice(m, tick_get_broadcast_device(), -1); 246 SEQ_printf(m, "tick_broadcast_mask: %*pb\n", 247 cpumask_pr_args(tick_get_broadcast_mask())); 248 #ifdef CONFIG_TICK_ONESHOT 249 SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n", 250 cpumask_pr_args(tick_get_broadcast_oneshot_mask())); 251 #endif 252 SEQ_printf(m, "\n"); 253 #endif 254 } 255 #endif 256 257 static inline void timer_list_header(struct seq_file *m, u64 now) 258 { 259 SEQ_printf(m, "Timer List Version: v0.10\n"); 260 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); 261 SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); 262 SEQ_printf(m, "\n"); 263 } 264 265 void sysrq_timer_list_show(void) 266 { 267 u64 now = ktime_to_ns(ktime_get()); 268 int cpu; 269 270 timer_list_header(NULL, now); 271 272 for_each_online_cpu(cpu) 273 print_cpu(NULL, cpu, now); 274 275 #ifdef CONFIG_GENERIC_CLOCKEVENTS 276 timer_list_show_tickdevices_header(NULL); 277 for_each_online_cpu(cpu) 278 print_tickdevice(NULL, tick_get_device(cpu), cpu); 279 #endif 280 return; 281 } 282 283 #ifdef CONFIG_PROC_FS 284 static int timer_list_show(struct seq_file *m, void *v) 285 { 286 struct timer_list_iter *iter = v; 287 288 if (iter->cpu == -1 && !iter->second_pass) 289 timer_list_header(m, iter->now); 290 else if (!iter->second_pass) 291 print_cpu(m, iter->cpu, iter->now); 292 #ifdef CONFIG_GENERIC_CLOCKEVENTS 293 else if (iter->cpu == -1 && iter->second_pass) 294 timer_list_show_tickdevices_header(m); 295 else 296 print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu); 297 #endif 298 return 0; 299 } 300 301 static void *move_iter(struct timer_list_iter *iter, loff_t offset) 302 { 303 for (; offset; offset--) { 304 iter->cpu = cpumask_next(iter->cpu, cpu_online_mask); 305 if (iter->cpu >= nr_cpu_ids) { 306 #ifdef CONFIG_GENERIC_CLOCKEVENTS 307 if (!iter->second_pass) { 308 iter->cpu = -1; 309 iter->second_pass = true; 310 } else 311 return NULL; 312 #else 313 return NULL; 314 #endif 315 } 316 } 317 return iter; 318 } 319 320 static void *timer_list_start(struct seq_file *file, loff_t *offset) 321 { 322 struct timer_list_iter *iter = file->private; 323 324 if (!*offset) 325 iter->now = ktime_to_ns(ktime_get()); 326 iter->cpu = -1; 327 iter->second_pass = false; 328 return move_iter(iter, *offset); 329 } 330 331 static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset) 332 { 333 struct timer_list_iter *iter = file->private; 334 ++*offset; 335 return move_iter(iter, 1); 336 } 337 338 static void timer_list_stop(struct seq_file *seq, void *v) 339 { 340 } 341 342 static const struct seq_operations timer_list_sops = { 343 .start = timer_list_start, 344 .next = timer_list_next, 345 .stop = timer_list_stop, 346 .show = timer_list_show, 347 }; 348 349 static int __init init_timer_list_procfs(void) 350 { 351 struct proc_dir_entry *pe; 352 353 pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops, 354 sizeof(struct timer_list_iter), NULL); 355 if (!pe) 356 return -ENOMEM; 357 return 0; 358 } 359 __initcall(init_timer_list_procfs); 360 #endif 361